Apparatus, method for controlling the apparatus, and storage medium

ABSTRACT

In a case where a skew of a document being conveyed is detected by a detection unit, an image reading apparatus notifies that documents having different sheet widths may be included in documents stacked on a stacking unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.17/064,380, filed Oct. 6, 2020, which claims priority from JapanesePatent Application No. 2019-187545, filed Oct. 11, 2019, which is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The aspect of the embodiments relates to an image reading apparatus thatdetects a skew of a document, a method for controlling the image readingapparatus, and a storage medium.

Description of the Related Art

There is provided an image reading apparatus that conveys a documentthrough an auto-document feeder (ADF) to read an image of the document,and generates image data by reading the document. For such an imagereading apparatus, if documents are stacked on a stacking unit (i.e.,manual document feeding unit) with the documents skewed, a jam may occurwhile the document is being conveyed, which may damage a document. Inaddition, the jammed document may damage a roller inside the ADF and anearby conveyance guide member. As a technique for solving theabove-described issues, Japanese Patent Application Laid-Open No2007-331908 discusses a printing apparatus that detects a skew of adocument by two sensors arranged to be line-symmetrical to a conveyancedirection, and adjusts a conveyance speed for the document conveyed by aconveyance roller based on a detected skewed amount.

As a method for detecting a skew of documents even for the documentshaving different sheet widths, a possible detection method is to provideseveral types of sensors arranged to be line-symmetrical to a conveyancedirection of a document at different arrangement widths. By employingthis method, for example, a skew of a document can be detected by theseveral types of sensors regardless of whether the document is an A2size sheet or an A4 size sheet having a width narrower than that of theA2 size sheet.

However, the following issues arise when the several types of sensorsare arranged. In a case where documents with different sheet widthsmixed are stacked on a stacking unit, the sensors erroneously detect thedifferent sheet widths as a skew of the documents, so that processing ofreading the documents is interrupted. In such a case, unless the user isnotified appropriately when the reading processing is interrupted, acause of the interruption of the reading processing, i.e., a mixed stateof the documents, cannot be resolved. Thus, the reading processingcannot be continuously executed no matter how much the user adjusts thedocument positions to prevent a skew of documents.

SUMMARY OF THE DISCLOSURE

According to an aspect of the embodiments, an apparatus includes aconveyance unit configured to convey a plurality of documents stacked ona stacking unit to a conveyance path, a reading unit configured to reada document conveyed by the conveyance unit, and a detection unitconfigured to detect, by using sensors, a skew of a document beingconveyed. The sensors are arranged on a straight line intersecting witha conveyance direction of a document in the conveyance path. In a casewhere the detection unit detects signals from the sensors as a skew ofthe document being conveyed, a notification that there is a possibilitythat documents having different sheet widths are included in theplurality of stacked documents is issued.

Further features of the disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an image reading system.

FIG. 2 is a diagram illustrating an external view of an operation unit.

FIG. 3 is a block diagram illustrating a configuration of a readingunit.

FIG. 4 is a sectional diagram of the reading unit.

FIG. 5 is a plan view of a document feeding tray of the reading unit andits periphery viewed from above.

FIGS. 6A, 6B, and 6C are plan views each illustrating the documentfeeding tray of the reading unit and its periphery viewed from above.

FIG. 7 is a plan view of the document feeding tray of the reading unitand its periphery viewed from above.

FIGS. 8A, 8B, 8C, and 8D are diagrams each illustrating an operationscreen displayed on a panel.

FIGS. 9A, 9B, and 9C are diagrams each illustrating an operation screendisplayed on the panel.

FIGS. 10A, 10B, and 10C are diagrams each illustrating an operationscreen.

FIG. 11 is a flowchart illustrating a method for controlling executionof a copy function.

FIG. 12 is a flowchart illustrating a method for controlling executionof a copy function.

FIG. 13 is a flowchart illustrating a method for controlling executionof a copy function.

FIG. 14 is a diagram illustrating a screen displayed on an operationunit of a personal computer (PC).

DESCRIPTION OF THE EMBODIMENTS

The aspect of the embodiments is directed to a technique of notifying auser of an appropriate method for restarting the reading processing in acase where the reading processing is interrupted due to a detection of askew of a document, in an image reading apparatus including, on astacking unit, several types of sensors capable of detecting differentsheet widths.

According to an aspect of the embodiments, it is possible to notify auser of an appropriate method for restarting reading processing in acase where the reading processing is interrupted because of a skew of adocument detected in an image reading apparatus having several types ofsensors on a stacking unit, which are capable of detecting differentsheet widths.

Hereinafter, exemplary embodiments of the disclosure will be describedin detail with reference to the accompanying drawings. The embodimentsdescribed hereinafter are not intended to limit the disclosure accordingto a scope of the appended claims, and not all the combinations offeatures described in the exemplary embodiments are required as thesolutions of the disclosure.

A first exemplary embodiment of the disclosure will be described. In thepresent exemplary embodiment, a job for reading a document is executed.Scanning is interrupted in response to a skew of a document having beendetected by skew detection sensors while the job is being executed. Adescription will be provided of a control method for notifying, inresponse to a detection of a skew of documents, a user of a method for acase of a skew and a method for a case where bound documents or mixedwidths documents are placed on an auto-document feeder (ADF).

FIG. 1 is a block diagram illustrating an image reading system accordingto the present exemplary embodiment. In the present exemplaryembodiment, a multi function peripheral (MFP) 101 and a personalcomputer (PC) 102 will be respectively described as one example of animage reading apparatus and one example of an information processingapparatus. The MFP 101 and the PC 102 are communicably connected to eachother via a network 100.

While an image reading system having a single information processingapparatus is illustrated in FIG. 1 , the MFP 101 and a plurality ofinformation processing apparatuses may be communicably connected via thenetwork 100. In the present exemplary embodiment, an image readingsystem including the MFP 101 and the PC 102 will be described, althoughthe exemplary embodiment is not limited thereto. For example, the MFP101 may be referred to as an image reading system.

Initially, the PC 102 will be described. The PC 102 can execute variousprograms, such as application programs. A scanner driver for enablingthe PC 102 to use a reading function of the MFP 101 and a scanningapplication for processing and organizing scanned images are installedin the PC 102. The PC 102 can use the reading function of the MFP 101 bytransmitting a scanning instruction to the MFP 101.

Next, the MFP 101 will be described. The MFP 101 includes a readingfunction for reading an image on a sheet and a printing function forprinting an image on a sheet. The MFP 101 further includes a filetransmitting function for transmitting image data to an externalapparatus.

While the MFP 101 will be described as one example of the image readingapparatus in the present exemplary embodiment, the present exemplaryembodiment is not limited thereto. The present exemplary embodiment isapplicable to an image reading apparatus that conveys a document to readan image of the document. For example, the image reading apparatus maybe a single-function scanner that does not have the printing function.The image reading apparatus may also be an apparatus that savesgenerated image data in an internal saving area. The image readingapparatus may also be a scanner that saves image data in an externalmemory (e.g., universal serial bus (USB) flash drive) attachable to anddetachable from the image reading apparatus via an external bus, such asa USB. In the present exemplary embodiment, for example, the imagereading apparatus includes various constituent elements described below.

A control unit 110 including a central processing unit (CPU) 111controls overall operation of the MFP 101. The CPU 111 reads a controlprogram stored in a read only memory (ROM) 112 or a storage 114 toexecute various control, such as reading control and printing control.The ROM 112 stores a control program that is executable by the CPU 111.A random access memory (RAM) 113 is a main storage memory of the CPU111, and used as a work area or a temporary storage area for loadingvarious control programs stored in the ROM 112 and the storage 114. Thestorage 114 stores print data, image data, various programs, and varioustypes of setting information. While it is assumed that an auxiliarystorage device, such as a hard disk drive (HDD), is used as the storage114 in the present exemplary embodiment, a non-volatile memory, such asa solid state drive (SSD), may also be used instead of the HDD.

While the one CPU 111 executes respective processes in operationsillustrated in the below-described flowcharts by using a single memory(i.e., RAM 113) in the MFP 101 according to the present exemplaryembodiment, other configurations may also be applicable. For example,the respective operations in the processing illustrated in thebelow-described flowcharts can be cooperatively executed by a pluralityof CPUs, RAMs, ROMs, and storages. A part of the processing may beexecuted by using a hardware circuit, such as an application specificintegrated circuit (ASIC) or a field-programmable gate array (FPGA).

An operation unit interface (I/F) 115 connects an operation unit 116 andthe control unit 110. FIG. 2 is a diagram illustrating an external viewof the operation unit 116. The operation unit 116 includes a panel 401for displaying an operation screen and a hard key input unit 402described below. Examples of the panel 401 include a touch-paneldisplay. The hard key input unit 402 includes various hard keys such asa start key 412. The user inputs an instruction by touching a keydisplayed on the panel 401 or by pressing a hard key provided on thehard key input unit 402. The panel 401 may be a display that has notouch-panel function. In such a case, the panel 401 may be any type thatincludes a scroll key for selecting a key displayed on a display and anEnter key for entering the selected key as hard keys. The operation unit116 functions as a receiving unit for receiving a user instruction inputvia the panel 401 or the hard key input unit 402, and also functions asa display unit for displaying the operation screen on the panel 401 asnecessary.

Referring back to FIG. 1 , a reading unit I/F 117 connects a readingunit 118 and the control unit 110. The reading unit 118 reads an imageon a sheet to generate image data. The image data generated by thereading unit 118 is transmitted to an external device or printed on asheet. A specific configuration of the reading unit 118 will bedescribed below with reference to FIGS. 3 and 4 .

A printing unit I/F 119 connects a printing unit 120 and the controlunit 110. Image data to be printed is transferred to the printing unit120 from the control unit 110 via the printing unit I/F 119. Theprinting unit 120 receives a control command and the image data to beprinted via the control unit 110, and prints an image based on the imagedata on a sheet. An electrophotographic method or an ink-jet method maybe employed as a printing method of the printing unit 120. Further,another method such as a thermal transfer method may be employed as theprinting method as long as an image can be printed on a sheet.

The control unit 110 is connected to the network 100 via a communicationunit I/F 123. The communication unit I/F 123 transmits image data andinformation to an external device connected to the network 100, andreceives print data and information from an information processingapparatus connected to the network 100.

<Configuration of Reading Unit>

A hardware configuration of the reading unit 118 will be described withreference to FIGS. 3 and 4 . FIG. 3 is a block diagram illustrating aconfiguration relating to control of the reading unit 118. A CPU 131controls the operation of the reading unit 118. The CPU 131 reads acontrol program stored in a ROM 132 to execute various types of control,such as reading control and communication with the control unit 110. TheROM 132 stores a control program that can be executed by the CPU 131. ARAM 133 is a main storage memory of the CPU 131, and used as a work areaor a temporary storage area for loading various control programs storedin the ROM 132. The CPU 131, the ROM 132, and the RAM 133 may berealized by a microcontroller including therein an integrated circuit inwhich respective functions thereof are embedded.

The reading unit 118 further includes an image processing unit 142, acharge coupled device (CCD) sensor unit 144, a motor control unit 147, amotor 148, a document detection sensor 145, skew detection sensors 151,152, 153, and 154, and other sensors such as conveyance sensors 146. Thereading unit 118 is connected to the control unit 110 via the readingunit I/F 117.

The document detection sensor 145 detects that documents 203 are stackedon a document feeding tray 202. A detection signal output from thedocument detection sensor 145 is transmitted to the CPU 111 via thereading unit I/F 117.

The motor 148 is driven to rotate a pick-up roller 243, a separationdriving roller 244, a separation driven roller 245, a conveyance rollerpair 206, lead roller pairs 210 and 211, a platen guide roller 208, anda discharge roller pair 207 of the reading unit 118 described below. Themotor 148 is driven to move an exposure unit 213 and a mirror unit 214of the reading unit 118 described below.

In the present exemplary embodiment, the CPU 111 controls the motorcontrol unit 147 to control the driving of the motor 148. However, theconfiguration is not limited thereto. The driving of the motor 148 maybe controlled by the CPU 131 of the reading unit 118 controlling themotor control unit 147.

The skew detection sensors 151, 152, 153, and 154 detect the occurrenceof a skew of a document. Each of the skew detection sensors 151, 152,153, and 154 is arranged on a straight line intersecting with aconveyance direction of the document. In the skew detection, it isdetermined that the occurrence of a skew of the document occurs in acase where a temporal difference between times when the document isdetected by the respective skew detection sensors 151, 152, 153, and 154is greater than or equal to a threshold value. In addition, a thresholdvalue for the temporal difference used for detecting skew of thedocument by the pair of the skew detection sensors 151 and 152 and thepair of the skew detection sensors 153 and 154 is stored in the storage114. The detection signals output from the skew detection sensors 151,152, 153, and 154 are transmitted to the CPU 111 via the reading unitI/F 117. The skew detection sensors 151, 152, 153, and 154 will bedescribed below in detail with reference to FIG. 5 .

The conveyance sensors 146 are arranged on respective checking points onthe conveyance path of the document, and detect the occurrence of aconveyance error such as the document jam and the presence or absence ofthe document in the conveyance path. In response to the conveyancesensors 146 having detected the occurrence of the conveyance error, amaintenance screen (described below) is displayed on the panel 401.

Data read by the CCD sensor unit 144 is converted into a digital signalfrom an analog signal by an analog-to-digital (A/D) conversion unit (notillustrated). The digital signal is then converted into image data bythe image processing unit 142, and temporarily stored in the RAM 113 viathe reading unit I/F 117. Through the control executed by the CPU 111,the image data is stored in the storage 114.

Next, reading operation for reading an image of the document 203(hereinafter, also referred to as “scanning”) executed by the ADF willbe described with reference to a sectional diagram of the reading unit118 in FIG. 4 . FIG. 4 is a sectional diagram of the reading unit 118.

The reading unit 118 includes a document feeding tray 202, regulationplates 231 and 232, and a discharge tray 222. The regulation plates 231and 232 are movably arranged to be brought into contact with both edgesof the document 203 placed on the document feeding tray 202. Thedocuments 203 stacked on the document feeding tray 202 are conveyed anddischarged to the discharge tray 222.

The reading unit 118 includes the pick-up roller 243 serving as asheet-feeding unit, the separation driving roller 244, the separationdriven roller 245, the conveyance roller pair 206, lead roller pairs 210and 211, the platen guide roller 208, and the discharge roller pair 207.

The reading unit 118 includes the document detection sensor 145 and apost-separation sensor 143. The document detection sensor 145 detectsthe document 203 on the document feeding tray 202. The post-separationsensor 143 is arranged downstream of the separation driving roller 244in the conveyance direction of the document 203, and detects a document203.

The reading unit 118 further includes the skew detection sensors 151,152, 153, and 154 and the conveyance sensors 146, which are alsoarranged downstream of the separation driving roller 244. The skewdetection sensors 151, 152, 153, and 154 detect a skew in a widthdirection of the document 203, and the conveyance sensors 146 detect theoccurrence of a conveyance error, such as a document jam, and thepresence or absence of the document 203 in the conveyance path.

The reading unit 118 further includes a platen glass 212, a jump stand217, a reference white plate 218, a document positioning glass 221, anexposure unit 213, a mirror unit 214, a lens 215, and a CCD sensor unit144. The exposure unit 213 and the mirror unit 214 are movable in asub-scanning direction that is the side to side direction in FIG. 4 , bya wire (not illustrated) and a driving motor (not illustrated).

In FIG. 4 , the scanning is started in response to receiving a scanningexecution instruction from the user in a case where the document 203stacked on the document feeding tray 202 is detected by the documentdetection sensor 145.

When the scanning is started, the pick-up roller 243 supported by an arm(not illustrated) is moved downward and brought into contact with anuppermost document of the documents 203 stacked on the document feedingtray 202. The documents 203 are fed by the pick-up roller 243 andseparated one by one at a separation nip serving as a separation unit,formed by the separation driving roller 244 and the separation drivenroller 245. The separation driving roller 244 is made of a material,such as rubber, having friction slightly lower than that of theseparation driven roller 245. A torque limiter is arranged on a path fortransmitting driving force to the separation driven roller 245. Thus,the separation driven roller 245 is rotated in cooperation with theseparation driving roller 244 when a single document is fed thereto, andis not rotated when the number of fed documents is two or more. Thisconfiguration enables the documents to be separated one by one. Inaddition, a driving force may be input to the separation driven roller245 in the direction opposite to the conveyance direction of thedocument 203. A leading edge and a trailing edge of the document 203passing through the separation nip are detected by the post-separationsensor 143, and detection results thereof are taken as references oftimings of moving up and down the pick-up roller 243 and timings ofstarting and stopping the driving of the pick-up roller 243 and theconveyance roller pair 206. The document 203 that is conveyed one by oneby the separation driving roller 244 and the separation driven roller245 passes through the skew detection sensors 151, 152, 153, and 154,and is detected by a document passage detection sensor serving as one ofthe conveyance sensors 146. The reading unit 118 determines whether thefirst document 203 has passed based on the detection time. The document203 conveyed inside of the apparatus by the conveyance roller pair 206is conveyed to the platen glass 212 by the lead roller pair 210. Theplaten guide roller 208 is arranged to face the platen glass 212, andguides the document 203 passing through the platen glass 212 so as toprevent the document 203 from separating from the platen glass 212. Whenthe document 203 passes over the platen glass 212, a face of thedocument 203 that is in contact with the platen glass 212 is exposed tolight by the exposure unit 213, and an image of the document 203 is readin a main scanning direction and the sub-scanning direction. Lightreflected on the document 203 acquired as a result of the scanning istransmitted to the mirror unit 214 via a plurality of mirrors. Thetransmitted reflection light passes through the lens 215, and iscondensed and converted into electric signal data through the CCD sensorunit 144. The data output from the CCD sensor unit 144 is converted intoimage data by the above-described image processing unit 142, andtransferred to the control unit 110. The reference white plate 218 isused as a reference of reading luminance of the document 203. Thedocument 203 that has passed through the platen glass 212 is guided tothe lead roller pair 211 by the jump stand 217 and discharged to thedischarge tray 222 by the discharge roller pair 207. The CPU 111 rotatesthe respective rollers with a driving force of the motor 148 to conveythe document 203. A discharge sensor serving as one of the conveyancesensors 146 detects the document 203 discharged to the discharge tray222.

In the present exemplary embodiment, a reduction optical system whichcauses reflection light from the document 203 to form an image on theCCD sensor has been described as the optical system included in thereading unit 118. However, the optical system is not limited thereto.The optical system included in the reading unit 118 may be an equalmagnification optical system which causes reflection light from thedocument 203 to form an image on a contact image sensor (CIS).

In the operation of reading an image of the document 203 which isexecuted by the reading unit 118, while a case is described in which aposition of the optical system is fixed, and an image of the document203 is read while the document 203 is being conveyed by the ADF, thepresent exemplary embodiment is not limited thereto. A position of thedocument 203 may be fixed after the document 203 is conveyed to thedocument positioning glass 221, so that an image of the document 203 canbe read by the optical system being moved with the driving force of themotor 148.

A cover 250 covers a part of the conveyance path of the ADF. The cover250 is configured to be openable and closeable by being rotated about afulcrum shaft (not illustrated). The user can open the cover 250 toconduct work, such as jam-removal processing of removing a documentjammed in or stopped at the conveyance path. In addition, anopening/closing sensor (not illustrated) for detecting an opening stateand a closing state of the cover 250 may be arranged.

Hereinafter, the occurrence of a document jam in the conveyance path andthe occurrence of a skew in a document are collectively referred to as“conveyance error”. In a case where the document jam occurs, the usercan remove the document pinched between the rollers of the lead rollerpair 210 by pulling the document 203 in the direction opposite to theconveyance direction. In a case where a position of the document isclose to the discharge tray 222, the user can convey and remove thedocument by operating a knob (not illustrated) for manually rotating thelead roller pair 211.

In the present exemplary embodiment, a maintenance screen which clearlypresents how to remove the jammed document to the user can be displayedon the panel 401. For example, the maintenance screen is configured topresent to a user a method for removing a document by opening a coverand a method for removing a document from a conveyance path by using animage and a moving image. The maintenance screen will be described belowin detail.

<Skew Detection Mechanism>

FIG. 5 illustrates a skew detection mechanism according to the presentexemplary embodiment. Hereinafter, a skew detection operation which isexecuted by the reading unit 118 will be described with reference toFIG. 5 . FIG. 5 is a plan view of the document feeding tray 202 of thereading unit 118 and its periphery viewed from above. While the skewdetection mechanism is configured with a pair of two skew detectionsensors in the present exemplary embodiment, the skew detectionmechanism is not limited thereto. Any type of skew detection mechanismthat includes a plurality of pairs of skew detection sensors isapplicable.

The skew detection mechanism of the reading unit 118 is configured withthe pair of the skew detection sensors 151 and 152 and the pair of theskew detection sensors 153 and 154. The pair of the skew detectionsensors 151 and 152 are arranged downstream of the pick-up roller 243,the separation driving roller 244, and the post-separation sensor 143 inthe conveyance direction. The pair of the skew detection sensors 153 and154 are arranged downstream of the pair of the skew detection sensors151 and 152 in the conveyance direction. The pair of the skew detectionsensors 151 and 152 is arranged so that a distance therebetween isshorter than an A4R size sheet width, which is 210 mm. The pair of theskew detection sensors 153 and 154 is arranged so that a distancetherebetween is shorter than an A3 size sheet width, which is 297 mm,and longer than an A4R size sheet width, which is 210 mm. Documents Dare stacked on the document feeding tray 202, and edges of the documentsD are evened by the regulation plates 231 and 232 on the documentfeeding tray 202. Each of the regulation plates 231 and 232 iscooperatively operated by, for example, a linkage mechanism, so as to bepositioned at the same distance from the center of the conveyance pathof the document in the width direction (i.e., a position of thepost-separation sensor 143 in the width direction). With thisconfiguration, the documents D placed on the document feeding tray 202aligned against the regulation plates 231 and 232 are positioned at themiddle of the conveyance path in the width direction. The uppermostsheet of the documents D is conveyed to the position of the separationdriving roller 244 by the pick-up roller 243 and is fed. If a documentto be conveyed is not skewed, an A4R size document can be detected bythe pair of the skew detection sensors 151 and 152, and cannot bedetected by the pair of the skew detection sensors 153 and 154. An A4size document and an A3 size documents can be detected by both the pairof the skew detection sensors 151 and 152 and the pair of the skewdetection sensors 153 and 154.

FIGS. 6A, 6B, and 6C are each a plan view of the document feeding tray202 of the reading unit 118 and its periphery viewed from above,illustrating an example of operation when bound documents are conveyed.FIG. 6A illustrates a skewed state where the front edges of thedocuments are not deformed, which is an ideal state for skew detection.FIG. 6B illustrates a state where a skew begins to occur and the frontedges of the documents are deformed, which is frequently occurs inpractice. FIG. 6C illustrates a state which occurs in a case where thedocuments are conveyed continuously from the state illustrated in FIG.6B.

The configurations and functions of the skew detection sensors 151, 152,153, and 154, the pick-up roller 243, the separation driving roller 244,the post-separation sensor 143, the document feeding tray 202, and theregulation plates 231 and 232 are similar to those illustrated in FIG. 5.

In a state ideal for executing skew detection, a first document D1 isrotated about a staple ST, and a leading edge thereof has a shapeexpressed by a straight line extending from around the staple ST, in acase where bound documents are conveyed, as illustrated in FIG. 6A. Inpractice, while the side, with the staple ST, of the leading edge of thedocument D1 is stopped at a position of the separation driving roller244, the other side thereof without the staple ST is likely to beconveyed along the regulation plate 232 approximately in parallel to theconveyance path as illustrated in FIG. 6B. Thus, a skew seldom occursfor an inner portion of the document where a pair of the skew detectionsensors 151 and 152 are arranged. Thus, in order to detect theoccurrence of a skew in a large-size document, a pair of the skewdetection sensor 153 and 154 are to be used in addition to the pair ofthe skew detection sensor 151 and 152. When time has passed from thestate illustrated in FIG. 6B, the side of the leading edge of thedocument D1 without the staple ST is conveyed in the conveyancedirection, so that the document D1 becomes a state illustrated in FIG.6C. This turns on of the skew detection sensor 154 arranged on theoutside, thus enabling the skew detection for large-size bounddocuments.

FIG. 7 is a plan view of the document feeding tray 202 of the readingunit 118 and its periphery viewed from above, illustrating an example ofan operation when mixed documents having different widths are conveyed.In FIG. 7 , an A4R size document D1 and an A3 size document D2 areplaced on the document feeding tray 202. In the present exemplaryembodiment, documents having different sizes in the width directionorthogonal to the conveyance direction of the documents are placed andconveyed simultaneously, and image forming processing is executedaccording to the respective sizes. The function of performing such imageforming processing is referred to as “different-width mixed documentsize”. To use the function of different-width mixed document size, theuser has to enable the setting of the different-width mixed documentsize. The setting of the different-width mixed document size can berealized by the user operating the operation unit 116.

In FIG. 7 , since the regulation plates 231 and 232 are arrangedaccording to the large-size document D2, the ADF detects a documenthaving the width of the document D2. Thus, the pair of the skewdetection sensors 153 and 154 is used in addition to the pair of theskew detection sensors 151 and 152. In a case where mixed documentshaving different widths are placed, the occurrence of a skew of asmall-size document D1 cannot be prevented by holding the document D1between the regulation plates 231 and 232. Thus, the occurrence of theskew of the document D1 is prevented by placing the document D1 with along side thereof aligned against either one of the regulation plates231 and 232. For example, the long side of the small-size document D1 isaligned against the regulation plate 232 on the rear side of thedocument feeding tray 202, i.e., the upper side in FIG. 7 .

<Processing at Detection>

In the present exemplary embodiment, the user is notified that a skewhas occurred in a case where a skew of a document has been detected, andthe following control is also performed: notifying a user of a handlingmethod for a case where a document is skewed and a handling method for acase where bound documents or mixed documents with different widthsmixed are placed on the ADF. Herein, a method for restarting readingoperation for document images after notifying the user of these handlingmethods will be described.

In a case where many bundles of documents are stacked on a documentfeeding tray, stapled documents may be erroneously set by the user.Thus, the occurrence of a skew may not be able to be prevented even ifthe user adjusts the width between the regulation plates 231 and 232 tothat of the documents. In view of this, in a case where bound documentsare set, examples of information to be notified to the user to preventthe reoccurrence of a skew include information that prompts the user toremove stapled documents from the bundle of documents.

In a case where mixed documents having different widths are set,possible examples of information to be notified to the user to avoid theabove-described erroneous skew detection include information thatprompts the user to make the setting of the different-width mixeddocument size and information that suggests to the user that skewdetection of the skew detection sensors be disabled temporarily.

In some cases, the user has to open the cover 250 of the reading unit118 to remove a document in a case where a skew is detected. Forexample, in a case where reading processing of documents is interrupteddue to the detection of a skew at a timing when the fifth document isbeing conveyed, the user has to open the cover 250 of the reading unit118 to remove the fourth and/or previous documents. The detection of askew and a document jam at the conveyance path may occur at the sametiming.

Accordingly, in a case where a skew is detected, a method for removing adocument jammed in or stopped at the conveyance path is also notified tothe user in addition to the information for preventing the reoccurrenceof a skew, in the present exemplary embodiment. For example, themaintenance screen that clearly presenting a method for removing adocument to the user and the screen that displaying the information forpreventing the reoccurrence of a skew are both displayed in the presentexemplary embodiment. An example of a method for displaying the screenswill be specifically described with reference to FIGS. 8A, 8B, 8C and8D.

FIGS. 8A, 8B, 8C and 8D are diagrams illustrating examples of screensdisplayed on the panel 401 in a case where a skew is detected by theskew detection sensors 151, 152, 153, and 154 of the reading unit 118 inFIG. 3 .

FIG. 8A illustrates an example of a maintenance screen displayed as aninitial screen when skew is detected. For the sake of convenience, thisinitial screen is called “simple maintenance screen”. FIGS. 8B and 8Cillustrate examples of maintenance screens each of which displays a workprocedure for removing a document. These maintenance screens aredisplayed to a user who is unfamiliar with a method for resolving adocument jam. For the sake of convenience, these screens are called“detailed maintenance screens”. FIG. 8D illustrates an example of ascreen that is displayed while the operation for rereading the documentsis put on standby, after the document jam is resolved, in a case where askew is detected.

The CPU 111 interrupts the conveyance of a document in response to theskew detection sensors 151, 152, 153, and 154 having detected theoccurrence of a skew in reading a document by using the copy function orthe file transmitting function. The CPU 111 displays a simplemaintenance screen 801 illustrated in FIG. 8A on the panel 401.

Information 802 illustrates a method for removing a document to the userwith an illustration. Here, a case in which a cover is opened to removethe document is illustrated.

Information 803 notifies the user of the occurrence of a skew of adocument. The information 803 illustrates that the user can proceed to ascreen for displaying a work procedure for removing a document byselecting a button “SEE DETAILED PROCEDURE” key 804.

The SEE DETAILED PROCEDURE key 804 is used for shifting the screen to adetailed maintenance screen which displays the work procedure forremoving a document.

In response to the CPU 111 detecting that the SEE DETAILED PROCEDURE key804 is pressed, the CPU 111 displays a detailed maintenance screen 805in FIG. 8B on the panel 401. The screen 805 displays, as an example ofthe work procedure for removing a document remaining in the conveyancepath, a message prompting the user to open the cover 250 of the readingunit 118. An area 806 is used for displaying a maintenance method. TheCPU 111 provides a method for removing a document to the user bydisplaying an animation or a moving image showing the opening andclosing of the cover 250 in the area 806. A key 807 is used for shiftingthe screen to a screen which displays the next work procedure.

When the CPU 111 detects that the key 807 is pressed in a state wherethe screen 805 is displayed thereon, the CPU 111 displays a detailedmaintenance screen 808 of FIG. 8C on the panel 401. In addition, thescreen 808 may be displayed when the opening of the cover 250 isdetected by an opening/closing sensor (not illustrated).

The screen 808 displays a description of work for removing a documentremaining in the conveyance path. An area 809 is used for displaying amethod for removing the document. The CPU 111 provides the method forremoving the document to the user by displaying an illustration or amoving image showing the method for removing the document in the area809. An illustration or a moving image that prompts the user to closethe cover 250 after removal of a document is also displayed in the area809.

If the CPU 111 determines that an error state can be cancelled based onoutputs from the conveyance sensors 146 and the opening/closing sensor(not illustrated), the CPU 111 displays a rereading standby screen 810illustrated in FIG. 8D on the panel 401. Information 811 notifies theuser that the processing can be restarted by pressing a start key 412after resetting the documents on the document feeding tray 202. In otherwords, the user can restart the operation of reading documents bypressing the start key 412. When the CPU 111 detects that the start key412 is pressed, the CPU 111 displays a screen for the copy function orthe file transmitting function, which has been displayed before skew isdetected.

The above-described plurality of causes of interruption of the readingprocessing and the plurality of handling methods for the causes aredisplayed on the rereading standby screen 810.

Information 812 notifies the user of the occurrence of a skew of thedocument. The information 812 also notifies the user that a widthbetween the regulation plates 231 and 232 (i.e., “document guide” inFIG. 8D) has to be adjusted to that of the document in order to preventthe reoccurrence of a skew as a method for handling a skew occurring ina document. The information 812 also notifies the user that stapleddocuments have to be removed from a bundle of documents in order toprevent the reoccurrence of a skew as the method for handling bounddocuments placed on the ADF. The information 812 further notifies theuser that the user has to stop rereading operation for documents and tomake the setting of the different-width mixed size document to avoid anerroneous skew detection, as the handling method for a case where mixeddocuments having different widths are placed on the ADF.

Information 813 notifies the user that the user can read the mixeddocuments having different widths by temporarily disabling the skewdetection function of the skew detection sensors to avoid erroneous skewdetection, as the handling method for documents having different widthsplaced on the ADF.

The user can temporarily disable the skew detection function of the skewdetection sensors 151, 152, 153, and 154 by pressing a key 814 inreading of the documents. When the CPU 111 detects that the start key412 is pressed in a state where the skew detection function is disabledby the key 814 being pressed, the CPU 111 temporarily disables the skewdetection function of the skew detection sensors 151, 152, 153, and 154in reading the documents. By pressing the key 814, the user can read themixed documents having different widths without making a stop of theconveyance operation due to the skew detection in rereading thedocuments. By selecting the key 814, the skew detection sensors 151,152, 153, and 154 are disabled for an optional period, e.g., a periodfrom when the key 814 is pressed to when a print job that is inexecution is completed.

A stop key 815 is used for stopping the copy function or the filetransmitting function that is in execution. The user can cancel the readdocuments and stop the processing that is in execution by pressing thestop key 815. In response to the CPU 111 having detected the press ofthe stop key 815, the CPU 111 displays a screen for the copy function orthe file transmitting function displayed before a skew is detected. Bypressing the stop key 815, the user can display the above-describedscreen and execute the copy function or the file transmitting functionafter making a new setting.

The rereading standby screen 810 is not displayed when the user followsthe information 812 and sets “MIXED DOCUMENT SIZE” by pressing a MIXEDDOCUMENT SIZE key 1002, or when the user follows the informationindicated by the key 814 to disable the skew detection sensors andexecutes scanning processing of the mixed documents. A screen 906 isdisplayed instead of the screen 810 as will be described in step S1313.FIGS. 9A, 9B, and 9C are diagrams each illustrating an example of ascreen displayed on the panel 401 when a document jam is detected by theconveyance sensors 146 in a state where a skew is not detected by theskew detection sensors 151, 152, 153, and 154 of the reading unit 118 inFIG. 3 .

FIG. 9A illustrates an example of a detailed maintenance screendisplayed as an initial screen when a document jam is detected with noskew detected. Similar to FIGS. 8B and 8C, FIGS. 9A and 9B eachillustrate an example of detailed maintenance screens which provides thework procedure for removing a document. FIG. 9C illustrates an exampleof a screen which stands ready for the operation of rereading thedocuments, displayed when a document jam is resolved.

The CPU 111 interrupts the conveyance of a document in a case where theoccurrence of a document jam is detected by the conveyance sensors 146when a document is being read by the copy function or the filetransmitting function. The CPU 111 displays a detailed maintenancescreen 901 of FIG. 9A on the panel 401.

A message prompting the user to open the cover 250 of the reading unit118 is displayed on the screen 901 as an example of the work procedurefor removing a document remaining in the conveyance path. A maintenancemethod is displayed in an area 902. The CPU 111 provides a method forremoving a document to the user by displaying an animation or a movingimage showing the opening and closing of the cover 250 in the area 902.A key 903 is used for shifting the screen to a screen displaying thenext work procedure.

When the CPU 111 detects the press of the key 903 in a state where thescreen 901 is displayed thereon, the CPU 111 displays a detailedmaintenance screen 904 of FIG. 9B on the panel 401. In addition, thedetailed maintenance screen 904 may be displayed when an opening/closingsensor (not illustrated) detects that the cover 250 is opened.

The content of work for removing a document remaining in the conveyancepath is displayed on the screen 904. The method for removing a documentis displayed in an area 905. The CPU 111 provides the method forremoving the document to the user by displaying, in the area 905, anillustration or a moving image showing the method for removing thedocument. The area 905 also displays the illustration or the movingimage that prompts the user to close the cover after removing thedocument.

When the CPU 111 determines that an error state can be cancelled basedon, for example, the conveyance sensors 146 and the opening/closingsensor (not illustrated), the CPU 111 displays a rereading standbyscreen 906 illustrated in FIG. 9C on the panel 401. Information 907notifies the user that the processing can be restarted by pressing thestart key 412 after resetting the documents on the document feeding tray202. In other words, the user can restart the reading operation fordocuments by pressing the start key 412. When the CPU 111 detects thepress of the start key 412, the CPU 111 displays a screen for the copyfunction or the file transmitting function displayed before a documentjam is detected. For example, a screen indicating in-execution of thecorresponding function as illustrated in FIG. 10C is displayed thereon.

A stop key 908 is used for stopping the copy function or the filetransmitting function that is in execution. The user can cancel the readdocuments and stop the processing that is in execution by pressing thestop key 908. When the CPU 111 detects the press of the stop key 908,the CPU 111 displays the screen for the copy function or the filetransmitting function displayed before a document jam is detected.

For specific control processing for displaying information forpreventing the reoccurrence of a skew, the copy function of the MFP 101will be described as an example.

First, settings for copying processing will be described. FIGS. 10A,10B, and 10C are diagrams each illustrating an example of a copy screendisplayed on the panel 401. FIGS. 10A and 10B each illustrate an exampleof a setting screen. FIG. 10C illustrates an example of an executionscreen displayed when the copying processing is being executed.

A user of the MFP 101 can select the copy function from a main screen(not illustrated) displayed on the panel 401. Buttons (icons) forstarting various functions of the MFP 101 (e.g., copy function, filetransmitting function, and file saving function) are selectivelydisplayed on the main screen.

The CPU 111 displays a setting screen 1001 illustrated in FIG. 10A inresponse to the user having pressed a copy function button in a statewhere the main screen is displayed.

The user can make various copy settings through the setting screen 1001.For example, the user can execute various settings with respect to thenumber of copies, a black-and-white or color printing mode, and atwo-sided printing mode. In addition, a copy job setting includesvarious setting items which are not illustrated. Thus, it is difficultto set all of the setting items in a single screen. Accordingly, theuser shifts the setting screen 1001 to an individual setting screen foreach of the setting items to make a setting of a plurality of functions.

The MIXED DOCUMENT SIZE key 1002 is a key for selecting whether toenable or disable the setting of the different-width mixed documentsize. The user can change the enabling and disabling of thedifferent-width mixed document size by using the MIXED DOCUMENT SIZE key1002. The setting screen 1001 illustrates a state where the setting ofthe different-width mixed document size is disabled.

When the CPU 111 detects the press of the MIXED DOCUMENT SIZE key 1002in a state where the setting screen 1001 is displayed thereon, the CPU111 displays a setting screen 1003 on the panel 401. The setting screen1003 illustrates a state where a setting of the different-width mixeddocument size is enabled as illustrated by the MIXED DOCUMENT SIZE key1004. It is assumed that the MIXED DOCUMENT SIZE key 1004 is displayedin a display mode different from a display mode of the MIXED DOCUMENTSIZE key 1002. A difference between the display modes of the MIXEDDOCUMENT SIZE keys 1002 and 1004 is not limited to the exampleillustrated in FIGS. 10A and 10B. For example, the MIXED DOCUMENT SIZEkey 1004 may be displayed in a shape different from that of the MIXEDDOCUMENT SIZE key 1002. Alternatively, the MIXED DOCUMENT SIZE key 1002may be displayed without blinking and the MIXED DOCUMENT SIZE key 1004may be displayed with blinking.

When the CPU 111 detects the press of the start key 412 in a state wherethe setting screen 1001 or 1003 is displayed, the CPU 111 startsexecuting the copying processing. The CPU 111 starts reading operationfor the documents by using the reading unit 118, and displays a copyexecution screen 1005 of FIG. 10C on the panel 401.

Next, a description will be described of, a method for controlling thedisplaying of information for preventing the reoccurrence of a skew inthe copying processing (illustrated in FIGS. 8A, 8B, 8C, and 8D) withreference to the flowcharts in FIGS. 11 to 13 . The copying processingwill be described as an example here.

The CPU 111 reads a control program stored in the ROM 112 or the storage114 to the RAM 113 and executes the control program to realizerespective processing operations (steps) of flowcharts illustrated inFIGS. 11 to 13 . Apart of the control program that realizes therespective operations of processing may be executed by another CPU(e.g., the CPU 131 of the reading unit 118), and the respectiveoperations of processing may be realized by the control program executedcooperatively.

Referring now to FIG. 11 , in step S1101, the CPU 111 determines whetheran execution instruction for a copy job is received. If the CPU 111determines that the execution instruction is received (YES in stepS1101), the processing proceeds to step S1102. If the CPU 111 determinesthat the execution instruction is not received (NO in step S1101), theoperation in step S1101 is executed repeatedly until the executioninstruction is received. More specifically, the CPU 111 determines thatan execution instruction for a copy job is received when the userpresses the start key 412 in a state where the setting screen 1001illustrated in FIG. 10A is displayed on the panel 401. In a case wherethe execution instruction for the copy job is received, the CPU 111displays the copy execution screen 1005 on the panel 401.

In step S1102, the CPU 111 sets (initializes) a value of a flag(hereinafter, called “scanning end flag”) to “FALSE”. The scanning endflag is a flag that indicates whether a series of processing of reading(scanning) images of documents is ended normally. The value of thescanning end flag is temporarily stored in the RAM 113.

The scanning end flag having a value of “TRUE” indicates that scanningis ended normally. The scanning end flag having a value of “FALSE”indicates that scanning is not ended normally. For example, in a casewhere a scanning stop instruction is received or execution of a copy jobis cancelled, the CPU 111 determines that scanning is not endednormally, and rewrites the value of the scanning end flag to “FALSE”.After executing the processing in step S1102, the CPU 111 advances theprocessing to scanning processing in step S1200. In step S1200, the CPU111 executes a series of processing relating to the scanning.

<Scanning Processing>

Referring now to FIG. 12 , details of the series of processing in stepS1200 relating to the scanning will be described.

In step S1201, the CPU 111 controls the reading unit 118 and conveys thedocuments 203 stacked on the document feeding tray 202.

In step S1202, the CPU 111 determines whether a conveyance error of thedocuments conveyed in step S1201 has occurred. The CPU 111 controls thereading unit 118 and acquires output values of the plurality ofconveyance sensors 146 and a rotation frequency of the driving motor.The CPU 111 then determines whether a document jam has occurred based onthe acquired values. If a document jam has occurred, the CPU 111determines that the conveyance error has occurred (YES in step S1202),and the processing proceeds to step S1209.

The CPU 111 acquires the output values of the skew detection sensors151, 152, 153, and 154. In a case where the setting of thedifferent-width mixed document size is disabled on the copy setting anda skew is detected by the skew detection sensors 151, 152, 153 and 154,the CPU 111 also determines that the conveyance error has occurred. Theprocessing then proceeds to step S1209.

In a case where a document jam does not occur, the CPU 111 determinesthat the conveyance error has not occurred (NO in step S1202), and theprocessing proceeds to step S1203. In addition, in a case where asetting of the different-width mixed document size is enabled or theskew detection function is temporarily disabled, the CPU 111 determinesthat the conveyance error has not occurred even if a skew is detected bythe skew detection sensors 151, 152, 153, and 154. Thus, the processingproceeds to step S1203.

In step S1203, the CPU 111 controls the reading unit 118 and reads adocument to generate data when the document 203 conveyed in step S1201passes through the platen glass 212. In step S1204, the CPU 111 controlsthe reading unit 118 and converts data read in step S1203 to image datathrough the image processing unit 142. The CPU 111 controls the readingunit 118 to temporarily store the converted image data in the RAM 113.

In step S1206, the CPU 111 saves the image data temporarily stored inthe RAM 113 in step S1204 in the storage 114. In step S1207, the CPU 111determines whether documents 203 are stacked on the document feedingtray 202. More specifically, the CPU 111 controls the reading unit 118and acquires the output value of the document detection sensor 145. TheCPU 111 determines whether the documents 203 are stacked on the documentfeeding tray 202 based on the acquired value. If the CPU 111 determinesthat the documents 203 are stacked on the document feeding tray 202 (YESin step S1207), the processing returns to step S1201, and the conveyanceof the next document 203 is executed. If the CPU 111 determines that thedocuments 203 are not stacked on the document feeding tray 202 (NO instep S1207), the processing proceeds to step S1208. In step S1208, theCPU 111 rewrites the value of the scanning end flag stored in the RAM113 to “TRUE” and ends the processing in step S1200. The processing thenproceeds to step S1103.

Next, operations which are executed when the occurrence of theconveyance error is determined (YES in step S1202) will be described. Instep S1209, the CPU 111 controls the reading unit 118 and interruptsscanning. The CPU 111 stops the conveyance and image-reading of thedocument based on the interruption of scanning. The processing thenproceeds to step S1210.

In step S1210, the CPU 111 deletes the image data temporarily stored inthe RAM 113 in step S1204. The processing then proceeds to step S1300.In step S1300, the CPU 111 executes recovery processing with respect tothe conveyance error. Through the processing in step S1300, recoveryfrom the conveyance error is performed and a scanning restart flagindicating whether to restart scanning is set. A flow of recoveryprocessing will be described below with reference to the flowchart inFIG. 13 .

In step S1211, the CPU 111 refers to a value of the scanning restartflag set through the series of recovery processing in step S1300. If thevalue of the scanning restart flag is “FALSE” (NO, in step S1211), theprocessing in step S1200 is ended, and the processing proceeds to stepS1103 in FIG. 11 . At this time, the CPU 111 closes a screen relating torecovery processing and shifts the screen to be displayed on the panel401 to the copy execution screen 1005.

If the value of the scanning restart flag is “TRUE” (if a value is not“FALSE”) (YES, in step S1211), the processing returns to step S1201. TheCPU 111 then executes processing of conveying the documents 203restacked on the document feeding tray 202 by the user. At this time,the CPU 111 closes a screen relating to recovery processing and shiftsthe screen to be displayed on the panel 401 to the copy execution screen1005.

In the processing in step S1211, if a scanning stop instruction isreceived in the recovery processing in step S1300, the CPU 111 ends thescanning processing while maintaining “FALSE” for the value of thescanning end flag. Thus, the copying processing can be stopped throughthe below-described processing.

<Recovery Processing with Respect to Conveyance Error>

Next, the recovery processing with respect to a conveyance error whichis executed in step S1300 will be described in detail with reference tothe flowchart in FIG. 13 .

In step S1301, the CPU 111 determines whether to notify the occurrenceof a skew of the document to the user. More specifically, the CPU 111acquires the output values of the skew detection sensors 151, 152, 153,and 154. If the CPU 111 determines that a conveyance error has occurredbased on a skew detected by the skew detection sensors 151, 152, 153,and 154 in a state where the setting of the different-width mixeddocument size is disabled in the copy setting, the CPU 111 determinesthat the occurrence of the skew is to be notified to the user (YES instep S1301), so that the processing proceeds to step S1302. if thesetting of the different-width mixed document size is enabled in thecopy setting, if the skew detection function of the skew detectionsensors 151, 152, 153, and 154 is temporarily disabled (no conveyanceerror is determined to have occurred even if skew is detected), or if askew is not detected (NO, in step S1301), the processing proceeds tostep S1311

The processing in step S1301 is executed so that the information forpreventing the reoccurrence of a skew is not to be displayed in a casewhere no skew is detected, a case where the setting of thedifferent-width mixed document size is enabled, or a case where the skewdetection function of the skew detection sensors 151, 152, 153, and 154is temporarily disabled.

In step S1302, the CPU 111 displays a screen including the informationfor notifying the user of the occurrence of the skew of the document onthe panel 401. More specifically, the CPU 111 displays the simplemaintenance screen 801 on the panel 401, and advances the processing tostep S1303.

In step S1303, the CPU 111 determines whether any event that triggers ashift of the display to the detailed maintenance screen 805 hasoccurred. More specifically, the CPU 111 advances the processing to stepS1304 if the “SEE DETAILED PROCEDURE” key 804 in the screen 801 ispressed, and advances the processing to step S1305 if the key 804 is notpressed.

In step S1304, the CPU 111 displays the detailed maintenance screen 805on the panel 401. The processing then proceeds to step S1305. In a casewhere an animation or a moving image is displayed in the area 806, theCPU 111 updates the area 806 displayed on the panel 401 at predeterminedintervals (e.g., 30 frame-per-second (FPS)). In addition, theinformation to be displayed in step S1304 can be changed as appropriate.For example, the CPU 111 acquires output values of various sensors, suchas the document detection sensor 145 and the conveyance sensors 146. TheCPU 111 then estimates a location of a document jam based on theacquired output values. Subsequently, the CPU 111 may display the methodfor removing the document based on the estimated location.

In step S1305, the CPU 111 determines whether the recovery from theconveyance error has been completed. More specifically, the CPU 111controls the reading unit 118 and acquires output values of theplurality of conveyance sensors 146. If the CPU 111 determines that nodocument is detected by any conveyance sensors 146 based on the acquiredvalues, the CPU 111 determines that the recovery has been completed (YESin step S1305). The processing then proceeds to step S1306. If the CPU111 determines that documents are detected by any one of the conveyancesensors 146, the CPU 111 determines that the recovery has not beencompleted (NO in step S1305). The processing then returns to step S1303.The CPU 111 updates the screen displayed on the panel 401 as necessary.

In addition, in step S1305, the CPU 111 may determine that the recoveryhas been completed if the closing of the cover 250 is further detectedby the opening/closing sensor (not illustrated). In such a case, the CPU111 advances the processing to step S1306 in a case where the closing ofthe cover 250 is detected by the opening/closing sensor in a state wherethe document is not detected by the conveyance sensors 146.

In step S1306, the CPU 111 displays, on the panel 401, the re-readingstandby screen (i.e., screen 810) which includes the information fornotifying the user of the occurrence of a skew of the document and theinformation for preventing the reoccurrence of a skew. The processingthen proceeds to step S1307. In step S1307, if the CPU 111 determinesthat the stop key 815 is pressed (YES in step S1307), the processingproceeds to step S1309. If the CPU 111 determines that the stop key 815is not pressed (NO in step S1307), the processing proceeds to stepS1308.

In step S1309, the CPU 111 sets a value of a flag indicating whether torestart reading (scanning) of the document image (hereinafter, referredto as “scanning restart flag”) to “FALSE”, and ends the series ofrecovery processing. In addition, the scanning restart flag istemporarily stored in the RAM 113. The processing then proceeds to stepS1211 when the recovery processing is completed.

In step S1308, if the CPU 111 determines that the start key 412 ispressed (YES in step S1308), the processing then proceeds to step S1310.If the CPU 111 determines that the start key 412 is not pressed (NO instep S1308), the processing returns to step S1307. The CPU 111 thenwaits for the press of the key. In step S1310, the CPU 111 sets a valueof the scanning restart flag to “TRUE” and ends the series of therecovery processing. The processing proceeds to step S1211 when therecovery processing is completed.

Next, the processing to be executed when the CPU 111 determines that theoccurrence of a skew is not to be notified to the user (NO in stepS1301) will be described. In step S1311, the CPU 111 displays thedetailed maintenance screen 901 on the panel 401. The processing thenproceeds to step S1312. In a case where an animation or a moving imageis displayed in the area 902, the CPU 111 updates the area 902 displayedon the panel 401 at predetermined intervals (e.g., 30 FPS). In addition,the information to be displayed in step S1311 can be changed asappropriate. For example, the CPU 111 acquires the output values ofvarious sensors such as the document detection sensor 145 and theconveyance sensors 146. The CPU 111 then estimates a location of adocument jam based on the acquired output values. Subsequently, the CPU111 may display a method for removing the document based on theestimated location.

In step S1312, the CPU 111 determines whether recovery from theconveyance error has been completed. More specifically, the CPU 111controls the reading unit 118 and acquires the output values of theplurality of conveyance sensors 146. If the CPU 111 determines that thedocument is not detected by any conveyance sensors 146 based on theacquired values, the CPU 111 determines that recovery has been completed(YES in step S1312). The processing then proceeds to step S1313. If theCPU 111 determines that document is detected by any one of theconveyance sensors 146, the CPU 111 determines that the recovery has notbeen completed (NO in step S1312). Thus, the processing returns to stepS1311. The CPU 111 then updates the screen displayed on the panel 401 asnecessary.

In addition, in step S1312, the CPU 111 may determine that the recoveryhas been completed if the closing of the cover 250 is further detectedby the opening/closing sensor (not illustrated). In such a case, the CPU111 advances the processing to step S1313 if the closing of the cover250 is detected by the opening/closing sensor in a case where thedocument is not detected by the conveyance sensors 146.

In step S1313, the CPU 111 displays, on the panel 401, the rereadingstandby screen (i.e., screen 906) which does not include the informationfor notifying the user of the occurrence of a skew of the document andthe information for preventing the reoccurrence of a skew. Theprocessing then proceeds to step S1314. In step S1314, if the CPU 111determines that the stop key 908 is pressed (YES in step S1314), theprocessing proceeds to step S1316. If the CPU 111 determines that thestop key 908 is not pressed (NO in step S1314), the processing proceedsto step S1315.

In step S1316, the CPU 111 sets the value of the scanning restart flagto “FALSE” and ends the series of the recovery processing. Theprocessing proceeds to step S1211 when the recovery processing iscompleted.

In step S1315, if the CPU 111 determines that the start key 412 ispressed (YES in step S1315), the processing proceeds to step S1317. Ifthe CPU 111 determines that the start key 412 is not pressed (NO in stepS1315), the processing returns to step S1314. In step S1314, the CPU 111waits for the press of the key. In step S1317, the CPU 111 sets thevalue of the scanning restart flag to “TRUE” and ends the series ofrecovery processing. The processing proceeds to step S1211 when therecovery processing is completed.

As described above, when the scanning processing is completed after theseries of the scanning processing in step S1200 and the recoveryprocessing in S1300 for a case of the occurrence of the conveyance errorin the scanning processing, the processing proceeds to step S1103 ofFIG. 11 .

Referring back to FIG. 11 , in step S1103, the CPU 111 refers to a valueof the scanning end flag. If the value is “TRUE” (YES in step S1103),the processing proceeds to the printing processing in step S1104. If areferred value of the scanning end flag is “FALSE” (NO in step S1103),the processing in step S1104 is skipped. The processing then proceeds tostep S1105.

In step S1104, the CPU 111 transfers the image data saved in the storage114 in step S1206 to the printing unit 120. The CPU 111 controls theprinting unit 120 and prints an image on a sheet. When the printing ofthe image data saved in the storage 114 is completed in step S1206, theprocessing proceeds to step S1105.

In step S1105, the CPU 111 deletes the image data saved in the storage114 in step S1206 and ends the copying processing.

Through the above-described series of processing, the MFP 101 accordingto the present exemplary embodiment receives an execution instructionfor a copy job and executes the received copy job.

According to the present exemplary embodiment, in a case where theoperation of conveying documents is stopped because a skew is detected,the user can restart the operation for reading the images of thedocument after checking the method for the case of a skew and the methodfor the case where bound documents or mixed widths documents are placedon the ADF, as described above.

According to the present exemplary embodiment, a method for removing adocument can also be notified to the user in a case where a skew isdetected. Thus, in a case where a skew of a document is detected by theskew detection sensors, the user can remove the document while checkinga method for opening a cover or a method for removing a document jammedin or stopped at the conveyance path.

The CPU 111 can control whether the notifying of the occurrence of askew to a user is executed. For example, in a case where a document jamoccurs in a state where a skew is not detected, i.e., in a case wherethe cause of the conveyance error is not the occurrence of a skew, theCPU 111 can display a maintenance screen displaying a method forremoving the document without the information for preventing thereoccurrence of a skew displayed. In a case where the setting of thedifferent-width mixed document size is enabled or the skew detectionfunction of the skew detection sensors is temporarily disabled, the CPU111 can also display the maintenance screen presenting a method forremoving the document without displaying the information for preventingan erroneous skew detection. Accordingly, the information for preventingthe reoccurrence of a skew or the information for avoiding an erroneousskew detection can be displayed when necessary.

According to the first exemplary embodiment, while the reading controlin the copy function has been described, the present exemplaryembodiment is also applicable to other functions for reading a document.Specifically, the present exemplary embodiment is also applicable to afile transmitting function for transmitting a document scanned by theMFP 101 to an externa apparatus. Moreover, the present exemplaryembodiment is also applicable to a saving function for saving a documentscanned by the MFP 101 in a saving area readable and writable by the MFP101.

The present exemplary embodiment is also applicable to a case where thePC 102 provides a scanning instruction to a single-function scanner tocause the scanner to scan a document, and stores the scanned image in asaving area of the PC 102. In such a case, a control program of the PC102 (e.g., scanner driver) and a reading control program of thesingle-function scanner cooperatively perform the above-describedcontrol. It is assumed that the single-function scanner includesconstituent elements necessary for reading a document and exchangingdata with the PC 102, from among the constituent elements illustrated inFIGS. 1, 3, and 4 . The shape and the external view of the conveyancepath for feeding and reading a document may be changed as appropriate.

In a case where the present exemplary embodiment is applied to thesingle-function scanner, a notification of a skew or a document jam maybe provided on an operation unit (not illustrated) of the PC 102. Forexample, the PC 102 receives the information about the occurrence of askew from the MFP 101 and displays a screen relating to a document jamor a skew as illustrated in FIG. 14 on the operation unit of the PC 102.

A screen 1400 illustrates an example of a window displayed on theoperation unit of the PC 102. Information 1401 notifies the user that adocument has to be removed. The information 1402 notifies the user thatthe width between the regulation plates 231 and 232 has to be adjustedto that of the document in order to prevent the reoccurrence of a skewas a handling method for a skew of a document. The information 1402 alsonotifies the user that stapled documents have to be removed from abundle of documents in order to prevent the reoccurrence of a skew as ahandling method for bound documents placed on the ADF. The information1402 further notifies the user that the user has to stop rereadingoperation of the documents and to execute setting of the different-widthmixed document size in order to avoid an erroneous skew detection as ahandling method for mixed documents having different widths placed onthe ADF.

As described above, the disclosure is applicable to an image readingapparatus capable of detecting a skew of a document and a system thatincludes the image reading apparatus.

As illustrated in FIG. 2 , the first exemplary embodiment has beendescribed based on the assumption that hard keys are used as the startkey 412 and the stop key. However, the present exemplary embodiment isnot limited thereto, and the keys or a part of the keys described ashard keys in FIG. 2 may be provided as a soft key displayed on the panel401.

Embodiment(s) of the disclosure can also be realized by a computer of asystem or apparatus that reads out and executes computer executableinstructions (e.g., one or more programs) recorded on a storage medium(which may also be referred to more fully as a ‘non-transitorycomputer-readable storage medium’) to perform the functions of one ormore of the above-described embodiment(s) and/or that includes one ormore circuits (e.g., application specific integrated circuit (ASIC)) forperforming the functions of one or more of the above-describedembodiment(s), and by a method performed by the computer of the systemor apparatus by, for example, reading out and executing the computerexecutable instructions from the storage medium to perform the functionsof one or more of the above-described embodiment(s) and/or controllingthe one or more circuits to perform the functions of one or more of theabove-described embodiment(s). The computer may comprise one or moreprocessors (e.g., central processing unit (CPU), micro processing unit(MPU)) and may include a network of separate computers or separateprocessors to read out and execute the computer executable instructions.The computer executable instructions may be provided to the computer,for example, from a network or the storage medium. The storage mediummay include, for example, one or more of a hard disk, a random-accessmemory (RAM), a read only memory (ROM), a storage of distributedcomputing systems, an optical disk (such as a compact disc (CD), digitalversatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, amemory card, and the like.

While the disclosure has been described with reference to exemplaryembodiments, it is to be understood that the disclosure is not limitedto the disclosed exemplary embodiments. The scope of the followingclaims is to be accorded the broadest interpretation so as to encompassall such modifications and equivalent structures and functions.

What is claimed is:
 1. An apparatus comprising: a conveyance unitconfigured to convey a plurality of documents stacked on a stacking unitto a conveyance path; a reading unit configured to read a documentconveyed by the conveyance unit; and a detection unit configured todetect, by using sensors, a skew of a document being conveyed, thesensors being arranged on a straight line intersecting with a conveyancedirection of a document in the conveyance path, wherein, in a case wherethe detection unit detects signals from the sensors as a skew of thedocument being conveyed, a notification that there is a possibility thatdocuments having different sheet widths are included in the plurality ofstacked documents is issued.